Archive for the ‘Methods & techniques’ Category

Help Please: Future of Neural Engineering: From Job perspective

Tuesday, November 14th, 2006

Dear Members,
I am a prospective graduate student interested in taking up Neural Engineering under EE or Biomedical Engg for research. But I have a lot of concerns and need help from a person who knows about the field well.
1. I have studied VLSI, DSP, Image Processing, Wireless Communication, Control Systems and Embedded Systems as graduate and undergraduate courses and have some research interest in Neural Networks and Machine Learning(That’s how I got interested in Neural Engg and Prosthetics). Which of these subjects will be of help in Neural Engg/Prosthetics research. Which will be of most relevance. Please list them in the order of relevance(high->low).
2. What are the applications of the research ?
3. What is the research and JOB scope for this field? Are there any companies who recruit people with this specialisation? How is the job scene in academia? How many univs are doing research in this field in US? Please let me know about the career progression in academia, like how much time does it take to get full time academic position after PhD?
4. Especially, what are the applications of this research in Robotics?
5. What are the current problems and research themes in universities?
6. What imaging technologies are used in this research?

Though my queries may seem a bit ameteuristic, it is very important for me to get clarity on these doubts.
Hope my queries will be answered.
Thanking all of you in advance,
sudhi

Allen brain atlas completed

Friday, September 29th, 2006

A few days ago the Allen Institute for Brain Science issued a press release announcing the completion of the Allen Brain Atlas.

“The Allen Brain Atlas (ABA) is an interactive, genome-wide image database of gene expression in the mouse brain. A combination of RNA in situ hybridization data, detailed Reference Atlases and informatics analysis tools are integrated to provide a searchable digital atlas of gene expression. ”

(more…)

OpenStim: The Open Noninvasive Brain Stimulator

Tuesday, September 19th, 2006

Transcranial magnetic stimulation (TMS) is a popular technology for stimulating human cortical neurons, due to its safety, noninvasiveness, and efficacy. A TMS device is just a little coil of wire, through which 10,000 Amps of current is cranked during a period of only a few hundred microseconds; the resultant rapidly-changing magnetic field induces eddy currents in the brain. Depending on the protocol used, TMS can drive/inhibit a region of cortex corresponding to roughly a cubic centimeter or two, and is being explored for the treatment of depression, the reduction of auditory hallucinations during schizophrenia, and the alleviation of tinnitus and migraines. Thousands of papers on medicine and psychology have been written using this tool.

Yet the device itself is expensive and rare — they can run from $20,000 to $50,000 or even more, despite the fact that they are, in essence, a coil, a switch, a bank of capacitors, and a power supply. Much of the art lies in making the devices safe and fail-proof. Is it possible to hack/engineer a system that is safe, fault-tolerant, efficacious, and inexpensive? And furthermore, can we facilitate a community that will devise such devices, and share information about protocols and approaches to brain hacking?

This past August at Foo Camp, a hackers’ conference in Northern California, a group of people got together and set out to do just that. We are designing a safe, noninvasive, modular, and “open source” brain stimulator that will open up the field of circuit modulation to a wider audience. Members of the group include therapists and mental health professionals, engineers, programmers, and others interested in either the development of such devices, or the sharing of information on this front. Key to the design is safety — we want to make sure that the devices we create are as safe as devices on the market. Also, all the information is released under the Creative Commons “Attribution and Sharealike” license. This is a new model for “open source” medical device development — which may move it beyond the domain of simply creating “cool toys,” and to creating real devices.

You can find out more information, or contribute to the project, or learn from the project, at
http://transcenmentalism.org/OpenStim/

-Ed

Slice culture: Preserving circuitry in culture

Sunday, September 10th, 2006

As many of you know, my experimental background is in hippocampal culture. Recently, I attended a hippocampal slice culture workshop given by members of the Hayashi lab here at MIT. I never really knew too much about the pros and cons of slice culture. After seeing the technique, I wrote up a little summary of the major differences from the point of view of someone who uses culture:

  1. slice culture can be done quickly. if you’ve got the mediums made, it takes 10-15 mins start to finish!
  2. hayashi lab uses P7 rats. Anywhere from P0 to P10 is viable for slice culture. Younger is better for certain genetics work (eg. transfection with gene gun). at P7, you get about 20 slices/hippocampus.
  3. P7 rat hippocampus can be dissected with only the aid of a magnifying glass! It’s macroscopic.
  4. coronal slicing results in a mostly intact hippocampal circuit: DG->CA3->CA1. In vivo, synapses form at P10.
  5. slicing is done with a tissue chopper. a vibratome is too slow (faster = more viable slice culture). 300-350um slices are used for patching and/or imaging. you can go thicker for imaging-only.


The biggest advantage over culture seems to be that you get an intact-ish hippocampal circuit. The biggest advantage over acute slice is that you don’t need to slice every day (and wait for recovery 1 hour post-slicing).
Neat technique.

Neuroengineering and the MIT TR35 innovators

Thursday, September 7th, 2006

Today MIT’s Technology Review magazine released its annual list of innovators under the age of 35 who were nominated for recognition. Interestingly, almost a full quarter are doing work relating to or impacting the field of neuroengineering — including ways to tag synapses with quantum dots, activate neurons remotely, improve machine vision, classify whole-brain states for prosthetic purposes, and make nanowire arrays.

http://www.technologyreview.com/TR35/

place for mol biologist in neuroprosthetics?

Tuesday, August 29th, 2006

Im a molecular/cellular neurobiologist. I do however, have a deep interst in neural prosthetics, bionics research. Is there a place for me in this field?

Two interesting meetings

Saturday, August 26th, 2006

Biophysics of Biological Circuits:
From Molecules to Networks
Summer School
http://www.uam.es/otroscentros/inc/summerschools/summerschool2006/

Engineering Principles in Biological Systems
Cold Spring Harbor Meeting
http://meetings.cshl.edu/meetings/engine06.shtml

The Nernst/Goldman Equation Simulator

Sunday, August 13th, 2006

The Nernst/Goldman Equation Simulator

An awesome simulator of Nernst and Hodgkin-Goldman-Katz eqns for membrane potential given variable ion permeabilities… with a very slick interface and downloadable programs for Mac and Windows. Also, there is a flash-based web version, too.

A genetically encoded fluorescent amino acid

Sunday, July 2nd, 2006

A genetically encoded fluorescent amino acid — Summerer et al. 103 (26): 9785 — Proceedings of the National Academy of Sciences

Some cool silicon biology to add to the toolbox. Now you can tag proteins by using a nonsense codon that codes for a fluorescent amino acid-tRNA. This technique and similar ones could easily revolutionize cellular tracking of protein trafficking.

Presynaptic somatic membrane potential can influence EPSPs

Thursday, June 8th, 2006

Modulation of intracortical synaptic potentials by presynaptic somatic membrane potential : Nature

Very interesting work. Modulation of the somatic potential seems to influence the EPSP, as measured by paired patch recordings of two layer 5 cells in cortical slice. Somatic depolarization from resting potential to near threshold results in an increase in evoked EPSPs.

In synaptic physiology, we often make a point of distinguishing intrinsic changes (eg. membrane potential) from synaptic conductance changes. Now it looks like the line between those might be a bit blurry!

Here’s a N&V by Eve Marder too.